**Absolute value of a: **

This expression represents the magnitude of a variable without regard to its sign. It signifies the distance from zero on a number line. That is the absolute value of -6 is 6 because -6 is 6 unit from zero. Likewise the absolute value of+6 is 6 because it, too is 6 units from zero. It gives the symbols ¦A¦ where A is any number or variable.

**Sum of N values:**

N

Σ X_{i }indicates the sum of numbered (indexed) values. For example, if the Xi are

I=1

grades for the individual students in a class the sum of the X_{i }(grades) for the students in the class of N students, divided by N, gives the average grade.

**Angle: **

An angle is a set of points consisting of two rays with a common midpoint. It is given the symbol Ð.

**Percent: **

An expression used to indicate a fraction of the whole, such as 50% of 90 is 45. It is given the symbol %.

**Multiplied by: **

A mathematical operation that, at its simplest, is an abbreviated process of adding an integer to itself a specified number of times. It is given the symbols x, , or * (computer).

**Divided by**

A mathematical process that subjects a number to the operation of finding out how many times it contains another number. It is given the symbol ÷ or /.

**Greater than or equal to**

It is given the symbol >, and denotes one quantity is equal to or larger than another.

**Less than or equal to:**

It is given the symbol <, and denotes one quantity is equal to or smaller than another.